The present invention relates to a manually operated dispensing device for delivering ophthalmic solution to the surface of an eye in a desired spray pattern with an impact pressure on the eye that is comfortably tolerated by an individual.
Traditionally, eye wash with an ophthalmic solution such as an isotone (0.9%) solution of sodium chloride, have been performed by pouring a relatively large amount of solution into the eye. The solution is conventionally maintained in a flexible container, the sealing of which is broken when the solution is to be used. Thereafter, the flexible container is held above the contaminated eye and the container is squeezed to allow a flow of solution into the eye. Although the result most often is good, the eye being adequately rinsed, the method suffers from a number of drawbacks. The amount of solution which flows out of the flexible container when it is squeezed is undesirably high, resulting in a loss of solution and an undesirable wetting of clothes etc. In this regard an excess of solution used does not improve the rinsing of the eye. Also, a certain free space is required above the eyes of the individual to be treated, in order for the container to be held above the eyes. Moreover, each container can only be used once since, when the seal has been broken, the sterilization of the solution remaining in the container is destroyed.
In U.S. Pat. No. 5,152,435 there is shown a manually operated dispensing pump intended to provide a precise quantity of ophthalmic solution to the surface of an eye in a desired spray pattern with an impact pressure on the eye that is comfortably tolerable by an individual. By the pump, the solution is pumped from a nonpressurized container. Although the object of the pump as shown is to provide a desired diverging spray pattern with a low impact pressure, it has been found that the spray flow from a manually operated pump, operatively connected to a nonpressurized container, is difficult to control. The resulting spray flow depends too much on the person using the pump, which means that too weak a press or too hard a press on the actuator button will result in undesired flow properties, such as spray pattern, droplet size and impact pressure, in the flow which is produced. Moreover, when the pump has not been used for some time, the actuator button must be pressed down a number of times before solution has been transported through the pipe all the way up to the nozzle. This means that the delivery of solution takes some time, time which may be crucial for the recovery of the eye.
From SE 451 295 there is known another device for delivering ophthalmic solution to the surface of an eye. The device exhibits a container for the solution which container also contains a drive gas capsule. When the device is to be used, the capsule is penetrated and the drive gas is brought to expand inside a rubber pouch. By the expansion of the rubber pouch, the solution is brought to form a spray flow via a nozzle. The device has at least the drawbacks that it can only be used once, and that instructions are needed in order for the individual to understand how to use the device. It is easy to understand that an individual who has received chemical or physical contamination in the eyes, cannot read information on the device, which means that there is a risk of misuse of the device, leading to a fatal result for the eyes.
For other types of dispensing devices, such as nose sprays, shaving foam, cosmetic sprays, etc., it is known to use a xe2x80x9cbag-in-canxe2x80x9d concept in order to achieve a pressurized dispensing device without the use of halogenated compounds in the drive gas. The xe2x80x9cbag-in-canxe2x80x9d concept includes a pressure container having a closed bottom and an open top defining a neck, for accommodating a pressurized gas and a sealed, flexible pouch. The pouch, which accordingly is accommodated inside the container is made of an essentially diffusion proof barrier material and exhibits a valve which is integrated with a mounting cup adapted to fit the neck of the container. When the container is to be filled with liquid and drive gas, the drive gas is filled into the container first. Thereafter, the open neck of the container is sealed by the mounting cup being crimped onto the neck of the container. Now, the liquid is filled into the pouch via the valve in the mounting cup, so that a desired total pressure is achieved inside the pouch/container. Although the xe2x80x9cbag-in-canxe2x80x9d concept has been known for some time, it has not been suggested to use the concept in connection with a manually operated dispensing device for delivering ophthalmic solution to the surface of an eye.
None of the above identified prior art devices is directed to a manually operated dispensing device for delivering ophthalmic solution to the surface of an eye, which device can be used to deliver the solution in a desired non-excessive spray pattern, with a desired impact pressure and a desired droplet size, very soon after an eye contamination has occurred, without the need of special instructions for the use of the device, and which device can be used over and over again while retaining the sterilization of the solution.
Therefore, it is a primary object of the present invention to provide a manually operated pressurized dispensing device for delivering ophthalmic solution to the surface of an eye, very soon after an eye contamination has occurred, without the need of special instructions for the use of the device, and which can be operated from any position.
It is a further object of the present invention to provide a manually operated pressurized dispensing device for delivering ophthalmic solution to the surface of an eye, in a desired non-excessive spray pattern, with a desired impact pressure and desired droplet size.
It is a further object of the present invention to provide a manually operated pressurized dispensing device for delivering ophthalmic solution to the surface of an eye, which device can be used over and over again while retaining the sterilization of the solution.
The manually operated dispensing device of the present invention is provided for delivering ophthalmic solution to the surface of an eye, in a desired non-excessive spray pattern, with a desired impact pressure and desired droplet size, very soon after an eye contamination has occurred, without the need of special instructions for the use of the device, over and over again while retaining the sterilization of the solution.
The device according to the invention comprises a pressure container having a closed bottom and an open top defining a neck, for accommodating a pressurized gas and a pouch; a sealed pouch, for the ophthalmic solution, made of a barrier material and exhibiting a valve which is integrated with a mounting cup adapted to fit the neck of the container; and an actuator adapted to fit the mounting cup of the sealed pouch, comprising a nozzle member including a cylindrical tube member, adapted to interact with the valve, and an actuator button for activating the interaction between the nozzle member and the valve, in order to accomplish the desired spray pattern.
The nozzle member of the present pressurized dispensing device is designed to give the desired non-excessive spray pattern, with a desired impact pressure and a desired droplet size. Especially, this is achieved by the design of the cylindrical tube member, which exhibits a venturi passageway including a nozzle outlet which creates a conical spray pattern which diverges at an angle xcex1 in the range of between 6 and 12xc2x0 from the longitudinal axis C of the venturi passageway. By this nozzle member, being operatively connected with the pouch inside the container, there is provided a flow of said ophthalmic solution of 1-20 ml/10 sec, preferably 2-16 ml/10 sec, at a major droplet size of 20-400 xcexcm, preferably 35-90 xcexcm. A small droplet size will efficiently give a large specific rinsing surface of the spray and also the impact pressure will be low for each droplet, thus creating a comfortable spray pattern to the eye. An impact pressure of at least 0.1 g/cm2 but not more than 1 g/cm2 has proven to be efficient, yet comfortable to the eye.
By the bag-in-can concept, there is provided a pressurized device, adapted to give a very even and constant flow of the solution, without the use of halogenated drive gas. Moreover, the compressed drive gas, which normally consists of nitrogen gas or air, does not come in contact with the solution inside the pouch. The pouch is beneficially designed in an essentially diffusion proof multi-layer laminate, known per se and preferably comprising polypropylene (PP), oriented polyamide (OPA), aluminum (ALU) and polyethylene (PET). Advantageously, but not necessarily, the pouch is provided with longitudinal sealing edges, protruding at least 5 mm, preferably at least 7 mm, and even more preferred at least 10 mm from a filling body of the pouch. The filling body of the pouch has a lateral dimension, in its filled state, which is fairly equal or somewhat larger than a lateral dimension of said container. By the sealing edges (or flanges), the pouch is, to some extent, secured inside the container. This is the case since the protruding sealing edges will be pressed against the inner wall of the container. To further improve the securing of the pouch, in order for the connection between the mounting cup and the pouch not to let go if the container is dropped into the floor or the like, the inner surface of the container and/or the outer surface of the pouch may be provided with a friction enhancing surface.
Thanks to the device having an appearance identical to a conventional pressurized can (normally including a halogenated drive gas), there is not needed any special instructions for the use of the device. This means that any person who has received chemical or physical contamination in the eyes, may use the device directly, without hesitation about how to use it. Moreover, the ophthalmic solution will be delivered immediately, when the actuator button is being pressed down, which means that no time is lost before the eyes can be rinsed. A further major advantage is that no free space above the eyes of the individual is required for treatment, since the shower can be activated from any position.